1. Field of the Invention
This invention relates to a method and an apparatus for machining a hard, brittle and fifficultly-machinable workpiece with a grinding wheel made of superabrasive grains.
The term "grinding wheel made of superabrasive grains", as used in the present specification and the appended claims, means a circular or annular rotating abrasive wheel made by bonding superabrasive grains such as natural or synthetic diamond abrasive grains or cubic boron nitride abrasive grains. The term "hard, brittle and difficultly-machinable workpiece", as used herein, means a work piece which is generally machined by using a grinding wheel made of superabrasive grains, for example a ferrite or ceramic workpiece.
2. Description of the Prior Art
As is well known, in the machining of a hard, brittle and difficultly-machinable workpiece, for example in a fluting operation in the manufacture of reading magnetic heads by providing a number of grooves in nearly rectangular ferrite blocks, a grinding wheel made of superabrasive grains and the workpiece are moved relatively to each other in a predetermined machining direction.
In conventional machining operations, the relative feed speed of the workpiece and the grinding wheel should be maintained extremely low in order to perform good machining as one desires without causing "chipping" to the workpiece and breakage to the grinding wheel. In fact, as far as the present inventor knows, the above relative speed feed in conventional machining operations is 17 mm/second at the highest. Hence, the conventional machining operations take a considerably long time.